# Untrusted contribution executed by privileged CI

A trusted workflow fetches or loads contribution-controlled code, configuration, or dependencies and executes them with authority unavailable to the contributor.

**Candidate CWE:** [CWE-829](https://cwe.mitre.org/data/definitions/829.html)

## Test hypothesis

Map event → exact fetched revision → executed Makefile/test/install hook → token or environment authority. Verify current checkout protections, explicit opt-outs, manual fetches, and approvals. Use an owned fixture and harmless output; a `pull_request_target` trigger alone does not prove this chain. For GitLab, record fork/source configuration, parent execution project and trigger actor separately; verify protected-resource restrictions for the installed version.

## Evidence required

Concrete low-trust contribution path, executable file, workflow and action SHA, relevant policy/defaults, dummy-token fixture results, and source-supported privilege scope. Separate confirmed settings from maintainer-only facts.

## Rule out false positives

Only trusted base code executes; fork material is inspected exclusively as data; current checkout protections block the path; or no intended trust boundary is crossed.

## Playbook and command references

- [CI and releases: trace untrusted input into privileged work](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/supply-chain-ci.html) — Audit workflow events, shell interpolation, untrusted builds, artifact consumers, and release identity as one privilege chain.
- [GitLab pipelines: contribution, job token and runner boundaries](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/gitlab-pipeline-boundaries.html) — Trace GitLab execution context, included configuration, downstream inputs, job-token permissions and runner reuse using private synthetic fixtures.

[Find the associated command snippets](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/commands.html?q=CI%20and%20releases%3A%20trace%20untrusted%20input%20into%20privileged%20work)

## Referenced by these target playbooks

[OSS & self-hosted](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/oss.html) · [Cloud & containers](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/cloud.html)

## Report checklist

- [ ] Capture the affected version, configuration, identities, and object ownership.
- [ ] Preserve a valid baseline and a negative control.
- [ ] Reproduce the forbidden data access, action, or state change on controlled fixtures.
- [ ] Explain the intended security rule and why the observed behavior violates it.
- [ ] State prerequisites, uncertainty, cleanup, and the smallest demonstrated impact.

## Conditional ATT&CK mapping

- [T1195.001 · Supply Chain Compromise: Compromise Software Dependencies and Development Tools](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/attack.html#T1195-001) — **Only if:** A controlled reproduction shows maliciously modified dependency or development-tool content being consumed through a software supply chain, such as a substituted reusable build action. **Not established by:** An old vulnerable dependency, an SBOM finding, or arbitrary CI log access does not prove supply-chain compromise. Show the manipulated component and consumer path.
- [T1195.002 · Supply Chain Compromise: Compromise Software Supply Chain](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/attack.html#T1195-002) — **Only if:** A controlled release/update workflow accepts modified application code or a substituted compiled artifact before delivery to its final consumer; prove consumption in a lab. **Not established by:** Access to a build log, ability to upload an unused artifact, or an ordinary software vulnerability does not establish malicious software distribution.

## Primary references

- [GitHub pull_request_target protections](https://docs.github.com/en/actions/reference/security/securely-using-pull_request_target)
- [MITRE CWE-829](https://cwe.mitre.org/data/definitions/829.html)
- [GitLab merge request pipeline trust](https://docs.gitlab.com/ci/pipelines/merge_request_pipelines/)

[Back to the complete vulnerability catalog](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/vulnerabilities.html)